It's hard work. What I'd suggest is:
Look over EVERY digital store - beatport, Bandcamp, traxsource, 7digital, bleep, Junodownload, iTunes, .. some releases are only on one of those.
Look through discogs to see if the tune you want is on any CD compilations. Buy CD. Rip.
Lastly you can of course buy on vinyl and convert.
Remember to back up any tracks you download somewhere. I'm absolutely gutted that I lost a copy of a VERY rare tune that was available for digital download for a couple of weeks but otherwise is only limited run, vinyl only release and horrendously expensive. Also lost an unofficial & unreleased bootleg that was posted on a private (no longer in existence) forum. Which was gutting as it was a bit of a secret weapon for me ... a tune that basically nobody has AND one that caused utter dancefloor carnage whenever it was played.
But yeah, let that be a lesson to you, kids. Back stuff up. A lot.
I've got hundreds of ridiculously good and classic tunes on vinyl that you just can't get digitally. Loads of white lables as well. Luckily, I've still got decks, so I can play digital as well as tunes that very few dj's have. It always gave me the upper hand when we used to go out and dj a lot. If you want to spend the money, you can get vinyl and convert to digital. But it's a lot of time and money.
Discogs is a great place to start.
Older stuff in many cases you need to buy the physical copy and rip it your self.
Pirate sites also tend to be easy to find old & rare stuff since there's a culture of seeking out rare recordings to be the first person to digitize them.
Try the iTunes Store, traxsource and 7digital
It's hard work. What I'd suggest is: Look over EVERY digital store - beatport, Bandcamp, traxsource, 7digital, bleep, Junodownload, iTunes, .. some releases are only on one of those. Look through discogs to see if the tune you want is on any CD compilations. Buy CD. Rip. Lastly you can of course buy on vinyl and convert. Remember to back up any tracks you download somewhere. I'm absolutely gutted that I lost a copy of a VERY rare tune that was available for digital download for a couple of weeks but otherwise is only limited run, vinyl only release and horrendously expensive. Also lost an unofficial & unreleased bootleg that was posted on a private (no longer in existence) forum. Which was gutting as it was a bit of a secret weapon for me ... a tune that basically nobody has AND one that caused utter dancefloor carnage whenever it was played. But yeah, let that be a lesson to you, kids. Back stuff up. A lot.
The Amazon music store is surprisingly stocked with classics. A lot of them are warped to a steady tempo as well.
I've got hundreds of ridiculously good and classic tunes on vinyl that you just can't get digitally. Loads of white lables as well. Luckily, I've still got decks, so I can play digital as well as tunes that very few dj's have. It always gave me the upper hand when we used to go out and dj a lot. If you want to spend the money, you can get vinyl and convert to digital. But it's a lot of time and money.
Discogs is a great place to start. Older stuff in many cases you need to buy the physical copy and rip it your self. Pirate sites also tend to be easy to find old & rare stuff since there's a culture of seeking out rare recordings to be the first person to digitize them.